1. Field of the Invention
The invention relates to an electrical connector having pressure contacts and more particularly to an improvement for such an electrical connector.
2. Discussion of Background and Relevant Information
The electrical connectors of this type comprise a socket provided with pressure contacts provided, for example, with a braid surrounded by a spring, as mentioned in French Patent 2,365,872 in the name of Applicant, or constituted by rocker elements as in French patent 2,422,270, or French patent 2,531,577 and its certificate of addition, likewise in the name of the same applicant, and a plug adapted to be inserted at least partially in the socket.
By virtue of the pressure exerted by the contacts and also that exerted by an ejection spring generally provided between the plug and the socket, so as to allow for a quick break (to avoid in particular the electric arc of breaking the circuit, etc.), it is necessary that the plug be retained in the socket by a latching means.
The latching means mentioned above is generally constituted by a hook provided on the socket and which is adapted to be in contact with a spur provided on the plug.
The hook is generally rockable by means of a pressure button.
These connectors may or may not comprise one or two safety discs, as disclosed, for example in French patents 2,212,655 and 2,270,696, in the name of the same applicant.
The insertion of connectors provided with at least one safety disc generally occurs in three steps: a pre-insertion axial movement, a rotation to align the respective contacts (the one or more discs thus undergoing this rotation), and a second axial pressure, until latching. The proper angular position of the plug and of the socket at the beginning of the maneuvers, as well as the translational and rotational guidance, are assured, for example, by a bayonet type system.
The connectors can, if desired, also comprise a sealing joint positioned between a portion of the plug and a portion of the socket.
It is desirable to provide only a single hook, so as to be able to allow for a sudden break of the current by relying upon it to free it, the contact springs and the ejection spring assuring the said break by sudden spacing of the plug and of the socket, the said plug being however, prevented from separating completely by the guidance means provided, as explained above (previously cited bayonet system, for example). In effect, a plurality of hooks would require a delicate manipulation if one desires that they be all freed in a synchronous manner so as to obtain the previously mentioned sudden break.
Under the effect of the pressure exerted, as explained above, by the contacts and by the ejection spring, the plug rests on the latching hook. It results necessarily that the plug is biased to turn around its retention point in a plane passing through its longitudinal axis and through the hook. In addition to a poor aesthetic appearance, the misalignment of the plug and of the socket plays a negative role, particularly on the efficacity of the contacts achieved (misalignment of the contacts of the plug with respect to those of socket), on the wear of the conductive braids, and on the sealing which can only be weakened by nonuniform crushing of the joint.
The solutions to this problem have been sought and studied for a long time.
To completely eliminate the above disadvantages, it has in particular been envisioned to multiply the number of latching means. Thus, certain electrical connectors comprise four hooks, or two hooks (with an insertion ring and/or bayonet system).
However, although these solutions may be appropriate for certain applications, they eliminate the advantage of having a single hook, as explained above.
This is why it has appeared until today, that the presence of a single hook necessarily had to be associated with the disadvantage of axial misalignment of the plug and of the socket. Given this situation, the research has been directed to two improvements: the limitation of inclination and the adaptation of this inclination.
To limit the inclination, it has been attempted to adjust, as best as possible, the diameters of the plug and of the socket, as well as the dimensions of the guidance means. However, it is clear that the tolerances of manufacturers resist the total elimination of a certain play between the plug and the socket.
With a view to adapting to the inclination, one positions the socket on a vertical wall, taking care preferably, that the hook be positioned upwardly, in a manner such that the weight of the cable connecting the plug makes it possible to compensate at least in part the said inclination.
With respect to the sealing, it has also been imagined to provide a joint which is thicker and/or has a lip and/or further has a nonconstant cross section.
Finally, one has also worked on the aesthetic aspects, by providing a rounding or an inclination of the surface of the socket, on the side of the plug.
It is clear that all of the means of limitation or adaptation mentioned above are gimmicks that do not resolve the question.